Vegetarians are less intelligent than non-vegetarians. That is not my opinion, that is prevailing scientific theory. In fact, current scientific thinking is that eating meat is what gave rise to intelligence and allowed Homo Sapiens (humans) to evolve. Let me explain.
To start with, we must assume for the sake of argument that evolution is scientific fact. Now, to be clear, evolution is still scientific theory. But, most objective individuals; if presented the scientific evidence for evolution versus the scientific evidence for creationism, would agree that evolution fits current scientific evidence and facts far more than creationism. So, for the sake of argument, in this piece we will assume that evolution is fact.
Now, if we trace human evolution back as far as current science allows, we arrive at a small primate that lived in Africa several million years ago called Australopithecus. There were actually two sub-species of Australopithecus, Australopithecus Africanus and Australopithecus Robustus. Africanus were small tree dwelling, vegetarian primates that primarily lived in trees but could also walk upright. Robustus was a more robust version of Australopithecus that was also vegetarian and apparently fed on roots and tubers instead of tree leaves and/or fruit like Africanus. Scientists have created molds of the brain cases of both Africanus and Robustus and have proven that the human brain could only have evolved from Australopithecus Africanus.
Australopithecus Africanus was a small, squat hominid that stood about 4 feet tall with a rather pronounced gut. This large gut was necessary in order to process the vegetarian fare that made up the bulk of Australopithecus Africanus’ diet. Vegetation is very tough to break down and thus requires a lot of processing, hence a large, complex digestive track is necessary. Now, these Australopithecus Africanus lived on the ancient African plain alongside the ancestors of today’s wildebeests, lions, cheetahs, hyenas, etc. As such, Australopithecus Africanus was probably a nice meal or snack for many of the fiercest land predators of the day.
Thus, the question must arise as to how these small, docile monkeys could have possibly survived, thrived and eventually dominated these fierce predators and competed with them for meat. The answer lies in the evolution of intelligence. These small Australopithecus Africanus found meat that was left behind by predators and other scavengers. Prevailing scientific theory holds that after an animal, such as a wildebeest or zebra was killed by a lion or cheetah and then scavenged by hyenas, the only meat left was the brain, buried deep in the skull and marrow, buried deep inside the bones. Australopithecus Africanus had enough intelligence to use tools to pry open the skulls of slain animals to get to their brains and break femurs and other bones in order to suck out the marrow. Brains and marrow are incredible, high-energy sources of protein. Therefore, these Australopithecus Africanus evolved into omnivores.
So what does this mean? Well, to understand that, one must first understand that meat is much, much easier to break down and digest than vegetation. As mentioned, a steady diet of vegetation requires a rather large and complex digestive track or gut. Now, guts are an extremely expensive organ, energy-wise. However, as these Australopithecus Africanus evolved to eating meat, they did not require these complex and energy-hungry guts, because meat could be digested much more easily. Freed from the requirements of their guts, Australopithecus Africanus was free to expend more energy in evolving other organs. And the organ that aided Australopithecus Africanus the most was its brain. Why? Because a better brain meant better tools with which to get at more meat. Australopithecus Africanus that were good tool builders survived and those that were poor tool builders did not survive. This led to an evolutionary adaptation that fed back on itself. More meat meant less guts which allowed the development of better brains. Better brains meant better tools, which meant more meat. Even more meat meant even less guts which allowed the development of even better brains…
OK, so who cares? Well, I care for one. But knowing how our human intelligence evolved, while interesting, is only really useful if we can use that knowledge and apply it to our society today. So what application does this knowledge have to our society today? Well, I would argue that it means that today’s vegetarians are in the early evolutionary stages of devolving their brain sizes and intelligence. A change in diet to meat is what allowed humans to evolve our human (Homo Sapiens) level of intelligence. Therefore, it follows that if a change in diet can have such a tremendous impact on the evolution of a species and since evolution is still occurring, then a change in diet back to vegetation should have just as significant an impact today as it did millions of years ago. Who knows, in a few million years we may have two species of Homo Sapiens, the tall, lean and intelligent carnivorous (or at least omnivorous) type and the short, squat and stupid vegetarian type with large guts.
With respect to my ancestors that struggled against lions, cheetahs and hyenas for survival back on the African plains, I think that I will take their cue and continue eating meat. It seems to have worked well for hominids for millions of years, why stop now?
Originally Published July 2003